Siemens SIRIUS 3RT1025-1AG20 Power Contactor — Size S0, Screw Terminals
The Siemens 3RT1025-1AG20 is a SIRIUS power contactor in the compact Size S0 frame, rated for motor switching at 7.5 kW in AC-2 duty at 400 V and 15.5 A in AC-4 duty at 400 V — the AC-4 figure governs reversing or inching applications where the contactor makes and breaks the load under full current. Main circuit screw terminals accept solid or stranded conductors up to 2x 10 mm² (AWG 8), while auxiliary and control circuit terminals handle up to 2x 4 mm² (AWG 12) — sized for typical motor branch circuits without needing terminal adapters.
Motor Duty Ratings & Short-Circuit Coordination
Rated at 7.5 kW AC-2 at 400 V (slip-ring motor starting) and 11 kW at 690 V; the same contactor delivers 10 kW at 500 V and 11 kW at 690 V — the higher voltage ratings let it serve 690 V industrial networks common in mining or marine installations. Short-circuit coordination: Type 1 requires a 63 A gL/gG fuse; Type 2 requires 25 A gL/gG. The 25 A fuse limits let-through energy to protect the contactor during a bolted fault, keeping it operational after the event.
Front face is IP20; terminal area is IP00 — install in a cabinet with at least IP2X door to meet touch-safe requirements. RoHS compliant per substance prohibitance date of 01.07.2006.
Built-in auxiliary contacts rated: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V — these cover control-circuit switching for PLC inputs, pilot lights, and interposing relays across common control voltages.